Often a model domain is too complex to create a single grid that accurately represents the area. Therefore, the user may have to create several grids and connect them using the Merge Two Grids tool.
To merge two grids, open the initial grid and then create a new layer for a new set of splines. These splines should extend from a location adjacent to the first grid and outline the new domain. Draw the farthest spline first, followed by the connection to the first grid and then the sides. When drawing the spline parallel to the first grid, ensure it is close to the edge. Generate the grid while ensuring that the number of cells in the I or J-axis of the new grid matches the number of cells connecting it to the first grid.
Suppose there are two grids (red and blue) that are visible, as shown in Figure Merge Two Grids#Merge Two Grids#Figure 1, that we want to merge together. The visibility of all other grids should be turned off. These two grids meet the requirement for merging, as described above. Left-mouse click (LMC) on either grid01 or grid02 in the Layer Control panel to select it.
Set the cursor in selection mode by selecting the selection button from the toolbar or press S key from the keyboard, then LMC on the first node at the contacting edge, and hold the SHIFT key, then LMC on the second node along the contacting edge (note that the two nodes must be on the same grid line where two grids contact). If two grids have more than one overlapped grid line, you should select the block of overlapped nodes. In both cases, you don't have to select all overlapped grid nodes where the connection will occur, but you can select part of them where the nodes of two grids are mostly close to each other. Once the segment is highlighted, we can select one of three ways to merge them.
(1) Click the Merge Two Grids button from the main toolbar or,
(2) Go to the Grid menu then select Merge Two Grids option or,
(3) RMC to display options, select Merge Two Grids option.
Figure Merge Two Grids#Merge Two Grids#Figure 2 shows options to merge two grids.
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Figure 1 Two 1. Two grids contacted.
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Figure 2 Figure 2. Options to merge two grids.
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After merging the two grids, a new grid layer (the result grid layer) is added to the Layer Control panel as shown in Figure Merge Two Grids#Merge Two Grids#Figure 3.
Grid+ also allows the merging of two grids in the case where there are overlapping cells as shown in Figure Merge Two Grids#Merge Two Grids#Figure 4. In this case, instead of defining a contacting gridline, we define a grid block and then select Merge Two Grids option.
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Figure 3 . A new grid is generated from merging two grids.
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Figure 4 4. Merge two grids by a grid block.
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